Deleting stuff from bootable USB stick

I am very much a NooB when it comes to Linux, I have tried a few times and failed. Knoppix , at first threatened to be "just like all the rest" and refuse to load etc, however coupla googles and the correct switch at boot for my system was found;
knoppix pci=noacpi, (switching acpi off in BIOS also works, but then I can't boot windoze, no cheering at the back please).
Anyway, I have now managed to transfer the files and boot from a usb stick. I know nothing about Linux files and filesystems, but when I look at the contents of the USB stick, I see a directory called knoppix which seems mainly to contain web pages and images, the web pages being in various languages, along with some faq and licence *.txt files. As space on the USB stick is at a premium, natch, is it safe to delete this stuff? (I guess that it has to be there for redistribution purposes, but I am not going to redistribute)
I read elsewhere that I can now delete isolinux.bin, is this true?